The present specification relates to a semiconductor device and to a method of making a semiconductor device.
In recent years, GaN/AlGaN high electron mobility transistors and GaN/AlGaN Schottky diodes have drawn a lot of attention regarding their potential to replace Si or SiC for use as High Voltage (HV) devices.
Devices of this kind often include a passivation layer that may be used to suppress the formation of interface states at a major surface of the substrate. During operation of the device, these surface states may be charged, leading to changes in the charge balance. For applications that involve switching, this may translate into differences between the static condition and the switching condition. During switching, charge trapping can reduce the current or increase the on-state resistance of the device. This degradation of the electric performance may be referred to as current-collapse in high voltage devices or dispersion in high frequency devices.